U.S. Pat. No. 3,344,022 discloses a wide variety of substituted quinoxaline 1,4-dioxide compounds. One particular structural type included within the broad genus of compounds disclosed is quinoxaline 1,4-dioxides with an acetyl group at the 2-position and a hydroxymethyl group at the 3-position. However, the said United States patent does not specifically identify any quinoxaline 1,4-dioxides with a 2-acetyl group and a 3-hydroxymethyl group, and it does not specifically teach how to make such compounds. In attempting to prepare 2-acetyl-3-hydroxymethylquinoxaline 1,4-dioxide by standard procedures, it has now been found that the products obtained are 1,3-dihydrofuro[3,4-b]quinoxaline, 4,9-dioxides of the formula ##SPC1##
Wherein R.sup.1 is hydrogen, or a moiety derived from the solvent (R.sup.1 OH) in which the reaction is run when said solvent is an alcohol.
Edwards, Bambury and Ritter, in the Journal of Medicinal Chemistry, 18, 637 (1975), describe the preparation and antibacterial activity of 1-hydroxy-1,3-dihydrofuro[3,4-b]quinoxaline 4,9-dioxide.
The compounds of the instant invention are derivatives of 1,3-dihydrofuro[3,4-b]quinoxaline 4,9-dioxide, and they are useful as antimicrobial agents for prophylaxis and therapy of economically important diseases in farm animals, and for the promotion of growth in farm animals.